“There could be the possibility of thunderstorms associated with this which could cause heavier downpours that may cause light mud flows in some areas of the Colby Fire Impact Area,” Glendora police said in a statement.

The yellow level alert includes the area north of Sierra Madre between the western city boundaries of Azusa/Glendora (Yucca Ridge) to the eastern boundary of properties on the west.

Glendora Police chief Tim Staab said the alert was issued as a precaution after the recent Colby fire chewed up much of the brush which would normally help keep the hillside in place.

Parking restrictions are in effect and residents are asked to remove trash cans as soon as it’s collected.